How important is placing the listener in the right position?

I finished to build my 28.4 system, now the fun begins. I was just wondering how important is that the listener position is the actual right one as in reality. As I can’t change the listener position, should I just change the height of all the speakers to make the listener position as close as the real one?

PS: When opening Spat in the shop section, there is a picture in the visualiser where you can see you added walls, stage, audience etc. Is it just a graphical feature, or are these objects affecting reflections and so on?

In general you would enter the loudspeaker positions as they are relatively to the listener (which actually depicts the sweet spot area).
For instance: in our studios, we have some loudspeakers about 1.30m height from the ground. This roughly corresponds to the ear height for a seated listener. => in Spat the loudspeakers are declared with z ~= 0m.

In practice, some tweaking is sometimes required. This has to be analyzed on a case by case basis, and this also depends on what you want to achieve.

Regarding the picture you mention: it’s mainly a graphical feature; although it’s possible to implement some “geometrically informed” audio processing; e.g. tutorial #19 presented an image source model to control Spat early reflections.

Earlier I was switching between panning methods, but until now the only one working in bformat, when I switch to hoa3d, nfchoa3d, or vbap3d with relative decoders it becomes a mess. I’m making some sort of mistake somewhere that I have to understand. But thanks, I will eventually get in touch if I can’t figure out what I do wrong.